/*! \page Linear_methodDoc Linear optimization 

Keyword: LINEAR

\section description Description

Perform energy optimization using the method very similar to the one described by Umrigar and coworkers in Phys. Rev. Lett. 98, 110201 (2007).  

\section options Options

\subsection reqopt Required 

No options are required.

\subsection optopt Optional

<table>
<tr> <td> <b>Option</b> <td> <b>Type</b> <td> <b> Default </b> 
     <td> <b>Description</b>
<tr> <td> VMC_NSTEP  <td> Integer <td> 100
        <td>  Number of VMC steps to perform per processor to collect statistics on the Hamiltonian matrix.  This is the most important variable to increase when improving the accuracy.
<tr> <td> MINIMUM_PSI0  <td> Float <td> 0.95
<td> Fraction of the original wave function to enforce per step.  This is a stabilization parameter.
<tr> <td> ITERATIONS  <td> Integer <td> 30 
     <td>  Number of optimization iterations. 
<tr> <td> WFOUTPUT <td> String <td>  runid.wfout 
     <td> Choose the filename to place an input deck for the final 
wavefunction and intermediate ones as the optimization
continues.
<tr> <td> MAX_VMC_NSTEP  <td> Integer <td> 8*VMC_NSTEP 
        <td> The optimization method will increase VMC_NSTEP automatically if certain significance requirements are not met in the Hamiltonian matrix.  This variable limits how much VMC_NSTEP can be increased.
<tr> <td> FIT_NCONFIG  <td> Integer <td> 200
     <td>  The number of configurations per processor used to evaluate the step size.  This is adjusted automatically up to MAX_FIT_NCONFIG to ensure significance.
<tr> <td> MAX_FIT_NCONFIG  <td> Integer <td> 8*FIT_NCONFIG
     <td>  Maximum number of configurations per processor to use to evaluate the step size.
</table>

*/
